实验性种植体周围炎小鼠模型的建立及TNF-α在模型小鼠牙龈组织中的表达

Establishment of mouse model of experimental peri-implantitis and expression of TNF-αin gingival tissue of model mice

目的:建立实验性种植体周围炎小鼠模型,探讨肿瘤坏死因子α(TNF-α)在实验性种植体周围炎模型小鼠牙龈组织中的表达,阐明其在种植体周围炎中的致病作用。方法:18只4周龄C57BL/6J雄性小鼠分为空白组、对照组和模型组,每组6只,拔除右侧上颌第一磨牙,即刻植入定制式种植体,愈合4周后模型组小鼠采用结扎诱导法建立种植体周围炎模型,空白组和对照组小鼠不做处理。空白组小鼠第0天(即结扎处理前)处死;对照组小鼠2周后处死;模型组小鼠采用5-0丝线环种植体颈部结扎处理2周后处死。获取各组小鼠上颌骨和牙龈组织标本,采用手术放大镜观察种植体周围牙龈组织大体形态表现,微计算机断层扫描(MicroCT)测量种植体周围骨高度和骨密度,RT-PCR法检测牙龈组织中TNF-αmRNA表达水平。结果:形态学观察,模型组小鼠种植体周围牙龈组织可见明显的红肿、质地变软和渗出,而空白组和对照组小鼠种植体周围牙龈组织无肉眼可见的炎症表现。与空白组比较,对照组小鼠种植体近端、远端、颊侧和腭侧骨高度及种植体周围牙槽骨骨密度差异无统计学意义(P>0.05),牙龈组织中TNF-αmRNA表达水平差异无统计学意义(P>0.05);与对照组比较,模型组小鼠种植体近端、远端、颊侧和腭侧骨高度及种植体周围牙槽骨骨密度明显降低(P<0.05),牙龈组织中TNF-αmRNA表达水平明显升高(P<0.05)。结论:采用结扎诱导法成功建立了实验性种植体周围炎小鼠模型,TNF-α在模型小鼠牙龈组织中高表达,其可能对种植体周围炎的发病具有促进作用。

Objective:To establish the experimental peri-implantitis mouse models,to investigate the expression of tumor necrosis factor-α(TNF-α)in the gingival tissue of the experimental peri-implantitis model mice,and to elucidate its pathogenic effect on peri-implantitis.Methods:Eighteen 4-week-old C57BL/6 Jmale mice were divided into blank group,control group and model group(n=6);the right and upper first molars were removed,and the custom implants were immediately implanted.After 4 weeks of healing,the mice in model group were used to establish the peri-implantitis models with ligation method;the mice in blank group and control group didn’t receive any treatment.The mice in blank group were killed on the 0 th day of ligation(before the ligation treatment);the mice in control group were killed on the second week without ligation;the mice in model group were killed on the second week of ligation of the neck of the implant with 5-0 silk thread.The upper jaw bone and gingvival tissue samples of the mice in various groups were obtained,and the morphology of peri-implant gingival tissue were observed with surgical microscope.Micro-CT scanning was used to measure the bone height and bone density around the implants and RT-PCR method was performed to detect the expession level of TNF-αmRNA in the gingival tissue.Results:The morphological observation showed that the gingival tissue around the implants in model group appeared obvious redness,edema,softening and exudation,while there were no visible signs of inflammation in blank group and control group.Compared with control group,the proximal,distal,buccal and zygomatic bone heights and the alveolar bone dellsity around the implants of the mice in model group were significantly reduced(P<0.05),and the expression level of TNF-αmRNA in the gingival tissue of the mice in model group were significantly increased(P<0.05).Compared with blank group,the proximal,distal,buccal and zygomatic bone heights and the alveolar bone density around the implants of the mice in control group had no statistical differences(P>0.05),and the expression level of TNF-αmRNA in the gingival tissue of the mice in control group had no statistical difference(P> 0.05).Conclusion:An experimental mouse model of peri-implantitis is successfully established with ligationinducing method.TNF-αis highly expressed in the gingival tissue of the model mice,which may have a role in promoting the pathogenesis of peri-implantitis.